[PATCH] docs: admin-guide: update description for kernel.hotplug sysctl

[Rasmus Villemoes]

It's been a few releases since this defaulted to /sbin/hotplug. Update
the text, and include pointers to the two CONFIG_UEVENT_HELPER{,_PATH}
config knobs whose help text could provide more info, but also hint
that the user probably doesn't need to care at all.

Fixes: 7934779a69f1 ("Driver-Core: disable /sbin/hotplug by default")
Signed-off-by: Rasmus Villemoes <linux@xxxxxxxxxxxxxxxxxx>
---
 Documentation/admin-guide/sysctl/kernel.rst | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/Documentation/admin-guide/sysctl/kernel.rst b/Documentation/admin-guide/sysctl/kernel.rst
index 1d56a6b73a4e..c24f57f2c782 100644
--- a/Documentation/admin-guide/sysctl/kernel.rst
+++ b/Documentation/admin-guide/sysctl/kernel.rst
@@ -333,7 +333,12 @@ hotplug
 =======
 
 Path for the hotplug policy agent.
-Default value is "``/sbin/hotplug``".
+Default value is ``CONFIG_UEVENT_HELPER_PATH``, which in turn defaults
+to the empty string.
+
+This file only exists when ``CONFIG_UEVENT_HELPER`` is enabled. Most
+modern systems rely exclusively on the netlink-based uevent source and
+don't need this.
 
 
 hung_task_all_cpu_backtrace
-- 
2.29.2